Moisture content determining apparatus



July 5, 1960 c. w. BRABENDER ETAL 2,943A79v MOISTURE} CONTENT DETERMINING APPARATUS 5 Sheets-Sheet 1 Filed June 13, 1955 c. w. BRABENDER ET L 2,943,479

MOISTURE CONTENT DETERMINING APPARATUS 5 Sheets-Sheet 2 5 w 5 mifl fi .E $1 m M? W a J H M M u aw A J 5 y F k wa I 5 MW%H WI I 1% W W41,

July 5, 1960 Filed June 13, 1955 July 5, 1960 c. w. BRABENDER ETAL 2,943,479

MOISTURE CONTENT DETERMINING APPARATUS 5 Sheets-Sheet 3 Filed June 15, 1955 y 1960 c. w. BRABENDER ErAL 2,943,479

MOISTURE CONTENT DETERMINING APPARATUS Filed June 15, 1955 5 Sheets-Sheet 4 Mal/75w July 5, 1960 c. w. BRABENDER 2,943,479

MOISTURE CONTENT DETERMINING APPARATUS Filed June 13, 1955 5 Sheets-Sheet 5 65' r-" -fi :y v I J L J,

J ,I fi r I A la-wraps MOISTURE CONTENT nurse APPARATUS Carl W. Brabender, Wayzata, and William R. Coyne,

Minneapolis, Minn., assignors to The Pillsbury Company, a corporation of Delaware Filed June 13, 1955, Ser. No. 514,947

19 Claims. (Cl. 73-76) This invention relates to apparatus for determining the moisture content of materials. More particularly, it relates to apparatus for determining the moisture content of pulverulent material such as flour wherein considerable need for quick determination is found.

In the processing and preparation of many products of a granular or pulverulent nature, it is highly desirable to be able to make quick determinations of the moisture content of the material from which the product is being made or of the end product itself, in order that proper adjustments to the machinery, methods or materials used may be made. In addition, it is highly desirable if such determinations can be made repeatedly without interruption and with sufficient rapidity so that one determination will confirm the previous determination whereby the observer may rely upon the first with confidence and without danger. Our invention is directed toward providing aparatus which will fulfill these needs.

It is a general object of our invention to provide novel and improved moisture determining apparatus which will make rapid determinations continuously without supervision and will record the same.

A more specific object is to provide novel and improved moisture determining apparatus which will make moisture determinations of materials such as flour at the rate of about one every ten minutes and will repeat the operation automatically and record the results.

Another object is to provide novel and improved moisture determining apparatus having novel means for removing the dried sample from a sample pan after a moisture determination thereof has been completed to thereby facilitate and expedite the execution of additional determinations.

Another object is to provide novel moisture determining apparatus which will automatically select and withdraw a sample of predetermined weight from a flow of material, which will automatically weight out a sample of predetermined weight of that material and will deposit the same within a sample pan upon a scale, which will automatically dry the sample and record its loss of moisture as a result thereof and which will automatically remove the dried sample from the sample pan and automatically cause the entire foregoing procedure to be repeated over and over Without supervision.

Another object is to provide improved moisture determining apparatus having novel and improved means of efiecting the sample drying portion of the procedure in order to effectively shorten the drying period, and having means for making the procedure automatic.

These and other objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

Fig. 1 is a side elevational view of one embodiment of our invention;

Fig. 2' is a plan view of the same;

2,43,479 aterrted July 5, 1960" Fig. 3 is a rear elevational view ofthe same embodiment of our invention;

Fig. 4 is a fragmentary side elevational view of the moisture content determining device on an enlarged scale viewed from the side opposite to that of Fig. 1;

Fig. 5 is a fragmentary rear elevational view of the drying and sample-withdrawing mechanism of the moisture content determining device taken on an enlarged scale;

Fig. 6 is a sectional view taken along line 6-6 of Fig. 2;

Fig. 7 is a plan view of the sample pan and pan driving support of the device with portions of the former broken away to show the latter, the view being taken on an enlarged scale;

Fig. 8 is a vertical sectional view taken along line 8-8 ofFig. 7;

Fig. 9 is a vertical sectional view taken along line 9-9 of Fig. 2;

Fig. 10 is a vertical sectional view taken alone line 10-10 of Fig. 2;

Fig. 11 is a side elevational view of the cam series connectedwith the timing motor, the view being shown on an enlarged scale;

Fig. 12 is a diagramatic view of the beam. balance and recording mechanism showing the relation therewith to the sample pan support;

Fig. 13 is a plan view of the electro-vane at the end of the beam balance, as shown in Fig. 12; and

Fig. 14 is a wiring diagram showing the electricallines connecting the various operating elements. of. the moisture content determining device.

One embodiment of our invention, as shown in Figs. l-l4, may include a frame indicated generally as F. Mounted upon this frame F at one side thereof is an electric motor 15 which drives, by means of a chain drive 16, an auger conveyor 17 which, as best shown in Fig. 2, extends transversely through a stack 18 and protrudes through the walls thereof. The auger conveyor 17 is mounted for rotation about its longitudinal, axis within an upwardly facing trough 19 which also extends across the entire width of the stack 18 and outwardly there from. The auger conveyor 17 has a discharge terminal 17a and the trough 19 has an associated discharge terminal 19a. The auger conveyor 17 when driven by the. motor 15 and chain drive 16, rotates in such a direction.

as to convey material toward these discharge terminals. The conveyor 17 and trough 1S together form a sampling mechanism for withdrawing representative samples from.

with the disc 23 so that its discharging terminal 24a which.

extends toward the front of the machine may be in loading position relative to the sample pan, as best shown in Figs. 1 and 4, or in raised position as shown in broken lines in Fig. 1. The discharging end 24a of the chute. 24 is open, as is its upper end portion 24b, so that flour may pass through either end at will, assuming its passage is not arrested by other elements as to be hereinafter described with respect to the discharge terminal 24a. The medial portion of the chute 24 is positioned directly below the discharge terminals 17a and 19a of the auger conveyor 17 and trough 19, respectively, so as to receive all of the flour conveyed by the conveyor 17.

Mounted on the frame F in position to receive flour from the rear end portion 24b of the tilting chute 24 when that end portion is swung downwardly, as shown in broken lines in Fig. 1, is a salvage conduit 25, the upper end of which is open. This salvage conduit 25 returns the flour received from the rear end portion 24b of'the chute 24 back into the main stream of flour which has passed the moisture determining machine.

Mounted on the mounting bracket 21 is a chute tilting motor 26 which by a gear 27 drives vertically a tilting rod 28 which has gear teeth 28a formed on one side thereof and engaging and cooperating with the gear 27. The upper end of the rod 28 is pivotally connected to the chute 24 so as to tilt the chute as the rod 28 is driven upwardly or downwardly by the motor 26. This can best be seen in Fig. 4-. The motor 26 is a reversible motor and is controlled in a manner to be hereinafter described.

Mounted on the disc 23 directly above the medial portions of the chute 24 is a pulsating vibrator 29 which carries a gate supporting arm 30 extending forwardly therefrom above the chute. At the forward end of the arm 30 is a depending gate member 31 which extends into the discharge terminal portion 24a of the chute. A catch 32 extends upwardly from the arm 30 in position to be engaged by a pivotable latch element 33, as shown in Fig. 4. To this latch element 33 there is connected a rearwardly extending cammiug lever 34 which swings with the latch element.

Also secured to the chute 24 is another electrical pulsating vibrator 35 which is controlled in a manner to be hereinafter described. A switch box housing H houses an upper and a lower limit switch 23a and 23b for the chute 24 and a pin 230 extends laterally from the disc 23 into the interior of the housing to engage these switches as the chute pivots.

Mounted adjacent to the chute 24 is a drying chamber 36. The discharge terminal portion 24a of the chute extends through one of the walls of the chamber and is free to tilt upwardly therewithin. A sample pan 37 which extends upwardly through an opening in the bottom of the chamber 36, as best shown in Fig. 5, is supported in material-receiving position relative to the discharge terminal portion 24a of the chute. This pan 37 is supported by a pan driver 38 which is supported by a hollow drive shaft 38a and is journaled on a mounting plate or tilting beam 39 and driven by a chain drive 40 which in turn is driven by a pan driving electric motor 41. This can best be seen in Figs. and 7. The under side of the pan 37 carries a depending centering or positioning pin 37a and a radially spaced depending drive pin 37b. The inside of the cup-shaped pan-driver 38 has a plurality of driving dogs 3812 one of which engages the drive pin 37]; of the pan to drive the same. Extending upwardly through the hollow drive shaft 38a is a pan support rod 42 with a pan support 43 at its upper end, the rod 42 being a part of a pan-weighing mechanism to be hereinafter described. The pan support 43 has a central recess within which the centering pin 37a extends, but the bottom of the pan 37 normally just clears the upper surface of the pan support 43.

The mounting plate 39 is pivotally supported by a pair of spaced depending journal plates 44 and 45 which extend downwardly from the chamber 36, as best shown in Fig. 4. An inverted channel member 46 is secured to the underside of the plate 39 and a pressure plate 47 extends downwardly from the medial portions thereof. Mounted on the side of the journal plate 44 is an electric beam tilting motor 48 which has a driving shaft 49 extending over the the journal plate 45 and carrying a cam 50 which engages the pressure plate 47 as it rotates with the driving shaft 49. This electric motor 48 is controlled in a manner to be hereinafter described and operates to tilt the mounting plate 39 so that it functions as atilting beam. A weight 51 is secured to the end of the tilting beam 39 opposite to that carrying the pan driver 38 so as to constantly urge the latter upwardly toward pan-engaging position, as shown in Fig. 5. The shaft 49 also carries a second cam 52 which normally holds a microswitch 53 in closed position but releases it to open position when a recess on the cam is opposite the switch as shown in Fig. 5. The microswitch 53 is positioned within the circuit to the beam-tilting motor 48 so as to interrupt the current thereto when the cam 5t? reaches he position shown in Fig. 5.

Secured to the weighted end portion of the tilting beam 39 is a chain 5 5 which extends upwardly and is secured to one end of a pivot lever 55, the other end of which car ries a weight 56 and the medial portion of which is mounted upon a pivot shaft 57, as best shown in Fig. 1.

The pivot shaft 57 extends in substantially the same direction as the tilting beam 39 and is journaled in the side wall of the drying chamber 36. An infrared lamp 58 is secured to the other end of the shaft 57 and swings therewith when the shaft pivots about its longitudinal axis. The lamp 58, when hanging straight downwardly from the shaft 57, is positioned directly above the sample pan 37 and directed thereinto.

Mounted upon the floor of the drying chamber 36 and extending upwardly therefrom is a post 59 upon which is pivoted a bar 60 carrying a weight 61 and a stirring rod 62 which extends downwardly into the pan 37 at its side walls and then toward and beyond the center of the pan and along its bottom. At the other end of the bar 60 and on the opposite side of the post 59 is an upwardly extending lever arm 63 which is positioned in the path of the swinging movement of the lamp 58 as best shown in Fig. 4, so that when the lamp 58 is swung sidewise away from the pan 37, the stirring rod 62 is also lifted to an aloft position out of the confines of the pan.

Mounted on the frame F below the drying chamber 36 is a weighing mechanism M. This mechanism M is preferably of the type shown in the United States Letters Patent No. 2,047,765, issued to Carl W. Brabender, dated July 14, 1936. The critical portions thereof are shown diagrammatically in Fig. 12 and include a beam balance 64 pivoting about a fulcrum 65 and supporting by one of its end portions, the pan support rod 42 which extends upwardly through the floor of the drying chamber 36. The other end portion carries a vane 66 which is positioned to pass between an electrovane 67 as that end portion is raised and also carries a vane 68 which is positioned to pass between an electrovane 69 when that end portion is raised still farther. The extreme end portion 70 of the beam balance 64 is positioned so that when an electrovane 71 is lowered, that end portion will pass through it and actuate the same just as the vanes 66 and 68 actuate the electrovanes 67 and 69 respectively, when they extend between opposite portions of each. These electrovanes are manufactured by the Brown Division, Philadelphia, Pennsylvania, of Minneapolis Honeywell Regulator Co., Minneapolis, Minnesota, and may be purchased from that company under the identification of part No. 353848l. They include a pair of spaced detecting coils which may be shielded from each other by passing a vane therebetween. When the vane is not shielding the detecting coils from each other, the electronic circuit de-energizes the relay of the unit and a circuit is closed to accomplish the desired action as hereinafter defined. The scale mechanism M may be purchased from the Brabender Corporation, Rochelle Park, New Jersey, and is identified by that company merely as a Brabender scale.

The electrovane 71 is carried by a gear mechanism 72 which is threadably mounted for vertical movement on a vertical threaded shaft 73, which is driven by a motor 74. A second threaded shaft 75 extends vertically through the gear mechanism 72 and threadably engages the same so that vertical movement of the gear mechanism 72 causes rotation of the shaft 75 about its longitudinal axis. A gear reduction mechanism 76 connects the upper end of the shaft 75 with a swingable recording pen 77 which inks the record of the extent of its swing upon a chart 78. This chart 78 is constructed, graduated and correlated with the extent of swing of the pen 77 so as to give a direct reading of the moisture content of the sample, the sample having been of a predetermined weight prior to having been dried. A time stamp mechanism 79 operated by a solenoid 80 records the time upon the chart 78 each time a recording is made.

Mounted upon and extending through one wall of the drying chamber 36 is a telescoping withdrawing or discharge chute D having a fixed upper portion 81 and a relatively movable portion 82, the latter of which has longitudinally arranged gear elements 83 on its outer surface cooperating with a drive gear 84 which in turn is driven by a reversible motor 85. When the gear 84 is driven, the lower portion 82 moves telescopically relative to the upper portion 81. A spacer element 86 extends downwardly from the lower end of the movable portion 82. A trip arm 87 extends laterally from the movable portion 82 and into a slot 88 formed by a housing 89 which covers an upper limit switch 90 and a lower limit switch 91. The chute is arranged so that the spacer element and the lower end portion 82 will extend within the confines of the pan 37 when at its lowermost position. A brush 92 is carried by the lower end of the portion 82 and this brush extends into the pan 37 and brushes the peripheral portions of the bottom of the pan to dislodge any particularly securely adhering particles of flour as the pan rotates.

The upper portion 81 is connected by a conduit 93 to a cyclone 94 which discharges the collected material into a collector 95. The upper end of the cyclone is connected to a suction creating mechanism 96 such as is used in a vacuum cleaner.

Associated with the various motors, relays, and moving parts is a timer controlled camming mechanism C which is best shown in Fig. 11 and which is electrically connected with the various parts as best shown in Fig. 14. For the sake of reference there is employed a timer motor 97 which drives a main cam-carrying shaft 98. This shaft carries a number of cams indicated as 99, 100, 101, 102,

103, 104, 105 and 106. Each of these cams has a switch 107, 108, 109, 110, 111, 112, 113 and 114 respectively associated therewith and the switches are connected electrically as shown in Fig. 14. Each of these cams has at least one recess formed in its .camming surface to release its switch during a part of its rotation with the shaft 98 and the remainder of its .camming surfaces cam the switches inwardly. Some of these cams have more than one recess and some of these switches are three-way switches as will be described in more detail hereinafter.

Cam 100 actuates switch 108 which is electrically connected to a solenoid valve 118 which controls the passage of air through an air conduct 119 which is connected to a source of compressed air (not shown). The conduit 119 terminates within the tilting chute 24 and is directed so as to dislodge particles of the previous sample which may have stuck within the chute.

At the start of the one of the cycles, the timer motor 97 is rotated and it turns the shaft 98 until the recess of cam 99 is opposite its switch member 107 which permits the switch member to move to closed position and thereby energize the two lO-second time delay relays 115, 116 shown only in the wiring diagram, Fig. 14, and the two-minute time delay relay 117, also shown only in Fig. 14. This switch member 107 as it closes, establishes a current also to the auger conveyor motor 15 and to the vibrator 35 on the chute 24. When these two l0-second relays close, they complete a circuit to the motor 26 which tilts the tiltable chute 24. As this motor 26 commences to tilt the :chute 24, the tilting action swings an arm or pin 230 which releases a microswitch 23a which in turn breaks the circuit leading to the timing motor 97 and stops the latter. The chute 24 is tilted by the chute tilting motor 26 when the current is closed thereto by the closing of the ten-second time delay relays 115, 116. As the chute 24 reaches the pan filling position, the microswitch 23b at the upper end of the path of the pin 230 is actuated to cut off the tilting motor 26 and thereby cease the tilting action. The vibrator 35 continues to operate until 9 /2 grams of flour have been deposited within the sample pan 37, and during that time the flour is fed into the feed chute 24 by the auger conveyor 17 and descends, as a result of the vibration, down the tilted chute and into the pan.

If the chute 24 has not returned to tipped-up position within two minutes, the two-minute time delay relays 117 are closed and establish a circuit to a warning signal (not shown) which will be sounded. In other words, the sample should be completely delivered within a twominute period into the confines of the sample pan 37, and if this is not the case, something has operated improperly and the mill supervisor will be apprised of that situation.

'When the sample pan 37 has received 9 /2 grams of flour, electrovane 67 is actuated by the tilting of the scale beam 64. This tilting, of course, is caused by the weight of the flour deposited into the pan 37 so that the vane 66 is introduced between the spaced coils of the electrovane 67. This electrovane closes a current to the pulsating vibrator 29 which closes the gate 31 on the chute 24 and permits the latch 33 to engage the catch 32 and lock the gate in position. This electrovane 67 also, at the same time, cuts off the current to the auger conveyor motor 15 so that it ceases to withdraw samples from the stack 18. At the same time, this electrovane 67 breaks the current to the pulsating vibrator 35 and thereafter only a dribble feed of the pulverulent material (created by material slipping past gate 31 as a result of the vibrations of vibrator 29) enters into the pan 37 until an additional /2 gram has been added to bring the weight of the sample within the pan to the 10 gram level. 'Of course, the entire mechanism may be adjusted so as to weigh out a 5 gram sample and make a determination of that weight of the pulverulent material. The weight of the sample causes the scale beam 64 to tilt farther so as to cause the vane 68 to pass between the spaced coils of the electrovane 69. This second electrovane 69 cuts off the current to the vibrator 29 and at the same time establishes a current to the chute tilting motor 15, which in turn tilts the discharge terminal 24a of the chuter 24 back to raised position. This electrovane 69 also cuts the current to the two-minute delay relay 117 so that the warning signal will not be sounded.

As the chute reaches the end of its upward tilting movement, the lower microswitch 23a associated therewith is closed by the actuating arm 230 to close the circuit to the timer motor 9.7 and commence it to again rotate the shaft 98 and the cam carried thereby. The closing of the lower microswitch 23a also cuts oif the current to the tilting motor 26. Thereafter the timing motor 97 continues to operate continuously for the remainder of the cycle. As the discharge terminal 24a of the tilting chute 24 tilts upwardly, the flour deposited in the chute 24 and prevented from being discharged therefrom by the gate 31 slides rearwardly and is discharged into the salvage conduit 25 from the rear end of the chute. This insures that none of the flour of the previous sampling is included with that of a subsequent sampling. At the same time, the latch 33 is cammed to released position at the end of the tilting action. The purpose of the latch 33 is to prevent excess hour from dropping into the pan 37 when the chute 24 starts to tilt upwardly at the end of the sample discharging operatlon.

The timing motor 97 continues to turn the cams 99- 106 until the recess on the cams 104 and 106 permits their associated switches 112 and 114 to close. Gm 104 controls two motors, one which rotates the pan (the pan rotating motor 41) and the other 48 which tilts the pan carrying beam. Both of these motors are actuated when the switch 112 associated with the recess of cam 104 closes. Cam 106 controls the current to the infrared lamp 58 so that when the associated switch 114 is permitted to close, the lamp is energized, and when the switch is forced to open position, the lamp is no longer energized. When the beam 39 is tilted, the lamp 58 is also swung to drying position above the beam 37. The cam 50 mounted on the driving shaft 49 of the beam tilting motor 48 bears against the pressure plate 47 which depends from the beam 39. When this pressure plate 47 is actuated by the beam tilting motor cam 50, the beam 39 is tilted to withdraw the chain 54 downwardly, which in turn causes the shaft 57 carrying the lamp 58 to pivot about its longitudinal axis and into drying position relative to the sample pan 37.

It will be recalled that the pan rotating motor 41 is mounted on the beam 39 and is connected with a chain drive 40 to the pan driver 48 which is a cup-shaped element having four pan driving dogs 48 thereon. Prior to the tilting of the beam 39, the pan 37 rests upon the pan support 33 of the scale, this pan support being a small disc with a central recess. The depending positioning pan 37a of the pan extends downwardly into the recess of the pan support 43, and the depending drive pin 37b is engaged by the pan driving dogs 38b to rotate the pan. As the beam tilts, the pan driver 38 engages and lifts the pan 37 off the pan support 43 and rotates the same about a vertical axis. The infrared lamp 58 is directed into the confines of the sample pan 37 as a result of swinging to drying position. The stirring rod 62 extends into the sample and the relative rotation of the sample pan causes the rod to continuously change the upper surface of the sample which is presented to the heat and drying action of the lamp 58. In this manner a much more relatively intense heat may be used, and since an infrared lamp has such penetrating qualities the combined action results in a rapid drying process. So long as the upper level of the sample is continuously changed, and there is moisture remaining in the sample, there is no danger of scorching which would cause inaccurate determinations. By continuously changing the upper surface of the sample, the drying operation is reduced to a matter of a very short period. The drying period continues until the timer motor 48 has turned the cams 104 and 106 sufficiently far to initiate action on the part of the beam tilting motor, as will be hereinafter described.

As the tilting beam 39 reaches the end of its tilting action (immediately prior to the drying operation), a cam 52 on the tilting motor 48 engages a microswitch 53 which breaks the current to the beam tilting motor 48 itself, and this motor remains idle for the entire drying period until, at the end of that period, when the cams 104 and 106 have been driven far enough by the timing motor 97 so that the recess on cam 104 terminates. At that point, the associated switch 112, which is a three-way switch, is pressed inwardly to close a separate circuit to the tilting motor 48, and cam 106 opens its associated switch 114 and thereby cuts off the current to the lamp 58. The tilting motor '48 then continues to operate and its pressure plate engaging cam 50 rotates, thereby permitting the pressure plate 47 to retract and permit the tilting beam 39 to commence to tilt back to its original position. When the tilting beam reaches its original position, the cam 52 on the beam tilting motor 48 releases the mcroswitch 53 which breaks the current to the beam tilting motor 48. As the beam tilts back, the pan driver 38 is lowered and the pan 37 is again engaged by the pan support 43 of the scale mechanism M. In so doing, the chain 54 to the lamp carrying shaft 57 is released and the weight thereon causes the shaft to pivot about its longitudinal axis, thereby swinging the lamp to one side to non-drying position.

When the tilting beam 39 is permitted to tilt back and the chain 54 connecting the beam to the lamp carrying shaft 57 permits the weighted shaft to pivot to swing the lamp sidewise, the lamp engages the lever arm 53 of the stirring mechanism and causes the sirrer 52 to be swung upwardly and laterally away from the pan.

The return of the pan 37 to the pan support 43 of the scale causes the scale to automatically register the weight of the dried sample and the interpolation of the loss of weight is displayed in the two places, namely upon the continuous chart 78 through the recording mechanism which is actuated by the third electrovane 71 by the beam of the scale, and also at a reading window on the scale. At the end of the drying action and return of the beam 39, cam 111 cuts in a switch which energizes elec trovane 71 which, when entered by the beam 64, actuates the motor 74 which drives shaft 73. The rotation of the shaft 73 causesthe gear mechanism 72 to lower until the extreme end 70 of the beam balance 64 passes between the coils of the electrovane to energize the same. When electrovane 71 is energized, it cuts off the current to the motor 74 so that the gear mechanism is arrested at that position. The downward movement of the gear mechanism 72 causes the shaft 75 to rotate about its longitudinal axis and, through the gear reduction 76, to swing the recording pen 77 laterally the appropriate distance to indicate accurately upon the chart 78, the moisture content of the sample. When the tilting beam has returned to its original position, the current to the infrared lamp 58 is shut off by cam 106 moving its associated switch 114 to open position.

After the recording has been completed as hereinbefore described, the timing motor 97 which is continuing to operate, will move cam 107 to energize a time stamp 79 for the chart 78. Thus the time of the determination will be stamped upon the chart opposite the recording made by the recording pen 77. Thereafter cams 102, 103 and 104 come in at approximately the same time. Actually earn 104 moves so as to permit its associated switch 112 to close first to energize the beam tilting motor 48 and the pan rotating motor 41. This motor 41 tilts the beam until stopped by its second cam 52 and limit switch 53, and the pan is lifted by the pan driver 38 and .rotated thereby. Thereafter cam 103 permits its associated switch 111 to close and this energizes the vacuum chute moving motor which is connected by gear mechanism 83, 84 to the vacuum chute D to lower its lower end 82 to a position immediately above the pan 37 carried by the scale. The limit switches 90, 91 at both ends of the path of movement of the chute prevent the chute from moving downwardly or upwardly too far. When the chute reaches a position immediately above the pan so that its spacer element 86 engages the bottom of the pan and its brush 92 extends into the confines of the pan against the bottom thereof, the downward movement of the lower part 82 of the chute D will be stopped because the microswitch 91 will cut off the vacuum chute moving motor 85. Immediately thereafter cam 102 permits its associated switch 110 to close to energize the vacuum inducing mechanism 06 which causes the vacuum chute D to draw the material upwardly out of the pan. As the pan rotates, the brush 92 dislodges all fine particles from the bottom of the pan and these are sucked upwardly through the vacuum chute D.

After the material has been drawn out of the pan, cam 102 cuts out the vacuum mechanism 96 and thereafter cam 103 cuts in the reversible vacuum chute moving motor 85 so that the lower portion 82 of the vacuum chute D is moved upwardly until the limit switch at the upper end of the path of movement is engaged, whereby the current to the vacuum chute moving motor 85 is again cut oil. Thereafter the second recess of cam 104 reaches its end and presses inwardly the switch 112, which is a three-way switch, and thereby closes a separate circuit to the beam tilting motor 48 to thereby tilt the beam back to the position Where the pan rests upon the pan support 43 of the scale. This switch 112 at the same time cuts off thecurrent to the pan rotating motor 41. At the end of the tilting action of the beam, the cam 52 on the beam tilting motor 48 cuts out the current to that motor. Thereafter cam 100 closes the current to a solenoid valve 118 which opens an air conduit 119 connected to a source of compressed air (not shown). The conduit terminates within the tilting chute as shown and is directed so as to dislodge particles of the previous sample which may have stuck within the chute. The timing motor 97 continues to rotate the cams until cam 1G0 cuts oii the current to the solenoid valve and cam 9? has its recess opposite its associated switch 107. It again energizes all of the timing relays l15117 and the entire operation commences to repeat itself.

Thus it will be seen that we have provided apparatus which will make rapid and accurate moisture content determinations, the entire operation of which is automatic and the operation cycle of which is relatively short so that repeated determinations will be provided thereby at approximately 10-l2 minute intervals. It should be noted that there is no supervision or manpower requirements in connection with the operation of this apparatus and that it can operate continuously without interruption to provide valuable data without being attended.

It will also be noted that this apparatus selects a truly representative sample from the flow of material and that this sample is taken automatically at the desired times without being attended. The sample is withdrawn from across the entire flow so as to be truly representative, and with a minimum possibility or probability of moisture being added thereto or withdrawn therefrom during its passage to the interior of the sample pan.

It should also be noted that this apparatus automatically and precisely weighs out accurate samples of a predetermined weight and deposits the same within the sample pan automatically. It also automatically weighs the sample and positions it for the ensuing drying operation. No time-consuming manual efiorts are required to insure that the sample is of the right weight or to transfer it after weighing to drying position. The entire operation is conducted without supervision.

The entire drying operation is also conducted automatically and the pan is automatically lifted from the scale and moved to a position where the pan can be rotated directly beneath the source of heat. The stirring apparatus is automatically inserted into the material within the pan and the pan is automatically rotated to provide a rapid drying operation without danger of scorching.

After the drying operation, the sample is automatically weighed. To accomplish this, the pan is automatical- 1y re-deposited on the scale and the stirring automatically ceases and the source of heat is automatically withdrawn. The loss in weight is automatically interpolated in terms of moisture content percentages and automatically recorded and stamped for future reference.

It will also be noted that our apparatus automatically withdraws the sample from the sample pan after the determination has been completed and automatically reinitiates the entire drying operation. From the above it can be readily seen that there is a substantial saving in time, labor and supervision through the use of our apparatus, and that a continuous record is provided of rapid and accurate determinations which permits the use of confirming determinations and prompt action to correct undesirable situations as revealed by these determinations. Thus it can be readily seen that our apparatus represents a distinct advancement in the field of moisture content determination and especially in such fields as the milling industry, wherein substantial savings can be accomplished through the quick detection and correction of undesirable situations or characteristics in the material being milled and the machinery accomplishing the milling operation.

It will, of course, be understood, that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of our invention.

What is claimed is:

1. Moisture-content determining apparatus comprising a sample pan, a balance supporting said sample pan and indicating the weight of the same and its contents, dryer mechanism mounted adjacent to and above said pan and directed into the interior of said pan to dry its contents, a suction conduit mounted adjacent said balance and having a movable intake terminal and a discharge terminal, said intake terminal being movable to a position adjacent to and above said sample pan, suction means connected to said conduit for inducing a negative pressure within said conduit and thereby causing the contents of said sample pan to be withdrawn therefrom and to pass through said conduit when its intake terminal is swung to such position, and control means including timer mechanism, said control means being connected to said first mentioned means and to the intake terminal of said suction conduit for moving the latter into such position and correlated with said balance and said dryer mechanism for causing said first mentioned means to induce a negative pressure within said conduit after the sample has been dried and weighed by said dryer mechanism and said balance respectively, to thereby automatically empty said sample pan.

2. Apparatus for determining the moisture content of material being passed through a conduit, said apparatus comprising sampling means for withdrawing samples from such conduit, a container supported adjacent said means, mechanism connected with said sampling means for introducing samples of that material into said container from said sampling means, automatic dryer mechanism connected to said sample-introducing mechanism for automatically drying the sample of material after it has been introduced into said container, measuring mechanism supporting said container and indicating the weight of the material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connected to said material-introducing means for controlling the same to cause the latter to introduce a sample of predetermined weight into said container, mechanism mounted adjacent said container for automatically removing the dried material from said container, and control mechanism connected to said sample-introducing mechanism and said sampleremoving mechanism and correlating the action of the latter with said measuring mechanism and automatically causing said sampleintroducing mechanism to introduce a new sample of material into said container after such dried material has been removed.

3. Apparatus for determining the moisture content of material being passed through a conduit, said apparatus comprising sampling means for withdrawing representative samples from such a conduit, a container, automatic mechanism mounted adjacent said container and said means for introducing samples of that material into said container from said sampling means, automatic dryer mechanism mounted adjacent said container and related to said sample-introducing mechanism for automatically drying the sample of material after it has been introduced into said container, measuring mechanism supporting said container and automatically indicating a function of the weight of such material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connected with said sample-introducing mechanism and controlling same to cause the latter to introduce a sample of predetermined weight into said container, mechanism connected with said dryer mechanism for consecutive operation relative thereto for automatically removing the dried material from said container after it has been dried, and control mechanism including a timing device connected to said sample-introducing means for automatically actuating said sample-introducing means to cause the same to introduce a new sample of material into said container after such dried material has been removed.

4. Apparatus for determining the moisture content of material being passed through a conduit, said apparatus comprising sampling means for Withdrawing samples from such a conduit, a container supported adjacent said means, means for introducing material into said container from said sampling means, cut-01f means operatively associated with said sample-introducing means for cutting off the flow of material into said container, automatic dryer mechanism disposed adjacent said container for automatically drying the sample of material after it has been introduced into said container, measuring mechanism supporting said container for indicating the weight of the material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connected to said cut-off means for controlling the actuation thereof to cause the cut-off means to cut oif the flow of material into said container when a sample of predetermined weight has been introduced thereinto, mechanism connected to said dryer mechanism for automatically removing the dried material from said container after it has been dried, and control mechanism connected to said sample-introducing means and said material-removing mechanism for automatically causing said sampleintroducing means to introduce a new sample of material into said container after said dried material has been so removed.

5. Apparatus for determining the moisture content of samples of material comprising a container for receiving a sample of predetermined weight of the material therein, automatic dryer mechanism mounted adjacent said container for automatically drying the sample of material after it has been introduced into said container, measuring mechanism supporting said container and automatically indicating the weight of such material after it has been dried within said container by said dryer mechanism, time controlled suction mechanism mounted adjacent said container in timed relation to said dryer and measuring mechanism for automatically removing the dried material from said container after it has been so dried and measured, and timer mechanism connected with said dryer, measuring, and suction mechanisms and correlating the action of each With that of the others.

6. Apparatus for continuously determining the moisture content of material being passed through a conduit, said apparatus comprising continuous sampling means for continuously withdrawing samples of such material from such a conduit, a container supported adjacent said means, means mounted adjacent said container for introducing such sample material into said container from said sampling means, control means connected with said sample-introducing means for automatically diverting the flow of material from said sampling means away from said container, automatic dryer mechanism for automatically drying the sample of material after it has been introduced into said container, measuring mechanism supporting said container and indicating the weight of the material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connected to said control means to cause introduction of a sample of predetermined Weight into said container, mechanism connected with said dryer mechanism for automatically removing the dried material from said container after it has been so dried and so weighed, and mechanism connected with said material-introducing means and said material-removing mechanism for automatically causing said material-introducing means after such dried material has been so removed from said container to redirect the flow of samples from said sampling means into said container.

7. Apparatus for continuously determining the moisture content of material being passed through a conduit, said apparatus comprising continuous sampling means for continuously withdrawing samples of such material from a conduit, a container supported adjacent said means, automatic means extending between said sampling means and said container for transferring such samples from said sampling means into said container, control means connected to said sample-transferring means for cutting ofi the flow of material into said container, automatic dryer mechanism mounted adjacent said container and connected to said control means for automatically driving off all moisture from the sample of material after it has been introduced into said container, measuring mechanism supporting said container and indicating the weight of the material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connected to said control means for cutting oif the flow of material into said container when a sample of such material of predetermined weight has been introduced into the container, mechanism connected with said dryer mechanism for automatically removing the dried material from said container, and mechanism connected to said sample-transferring means and said sampleremoving mechanism for automatically causing said sample-transferring means to redirect said samples into said container after such dried material has been removed from said container.

8. Apparatus for continuously determining the moisture content of material being passed through a conduit, said apparatus comprising continuous sampling means for continuously withdrawing samples of said material from such a conduit, a container adjacent said means, swingable material-transferring mechanism mounted adjacent said sampling means and said container to direct such samples from said sampling means into said container, control means for cutting ofi the flow of material into said container and for causing said transferring means to swing to a position where such samples will be diverted from said container, automatic dryer mechanism for automatically drying the sample of material after it has been introduced into said container, measuring mechanism supporting said container and indicating the weight of the material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connected to said control means and causing the same to automatically cut off the flow of material into said container when a sample of predetermined weight has been introduced thereinto, mechanism connected to said dryer mechanism for automatically removing the dried material from said container, and control mechanism connected to said swingable transfer means and automatically causing said transfer means to swing, after such dried material has been removed from said container, to a position where such samples will again be directed into said container to permit a new sample of material to be introduced thereinto.

9. Apparatus for determining the moisture content of samples of material comprising, a container for receiving a sample of material therein, mechanism adjacent said container for introducing into said container a sample of such material, automatic dryer mechanism connected with said sample-introducing mechanism for automatically drying such sample of material shortly after it has been introduced into said container, measuring mechanism supporting said container and indicating the weight of the material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connnected to said sample-introducing mechanism and controlling the same to cause the latter to introduce a sample of pre-determined weight into said container, and automatic sample-removing mechanism connected with said dryer mechanism for automatically removing the dried sample from said container shortly after it has been so dried and measured.

10. The structure as defined in claim 9, wherein said mechanisms are controlled to automatically function in order.

11. Apparatus for determining the moisture content of samples of material comprising a container for receiving a sample of material therein, mechanism for introducing into said container a sample of such material, dryer mechanism connected with said sample-introducing mechanism for drying such sample of material afterit has been introduced into said container, mechanismconnected with said introducing mechanism for automatically energizing said dryer mechanism shortly after the sample has been introduced into said container by said introducing mechanism and for automatically de-energizing said dryer mechanism after the sample has been dried, measuring mechanism supporting said container and connected with said dryer for automatically indicating the weight of the material after it has been dried within said container by said dryer mechanism, said measuring mechanism being connected with said sample-introducing mechanism for controlling the same to cause the latter to introduce a sample of predetermined weight into said container, and automatic sample-removing mechanism connected with said dryer mechanism for automatically removing the dried sample from said container shortly after it has been so dried and measured.

12. Sample selecting apparatus comprising a sample pan, a balance supporting said pan and indicating the weight of the material, a pulverulent material-carrying conduit having a discharge terminal discharging into said sample pan, and mechanism connected to said balance and said conduit and automatically causing, when a sample of given weight has been discharged from said conduit into said pan, the material following said sample through said conduit to be directed in a flow away from said pan and automatically causing the flow ofsuch material through said conduit to be subsequently redirected into said sample pan until a new sample of given weight has been received therein from said conduit, and dryer mechanism positioned adjacent said sample pan to permit the same to dry a sample contained therein, and time-regulated control mechanism connected to said dryer mechanism and said balance for automatically actuating said dryer mechanism when a sample of material has been deposited in said sample pan by said conduit to cause it to dry the same.

13. Moisture-content determining apparatus comprising, mechanism for supporting and weighing a sample of the material the moisture content of which is to be determined, sample-drying mechanism mounted adjacent to said weighing mechanism in position to dry the sample while so supported and connected with said weighing mechanism to automatically commence to dry the sample when the entire sample has been deposited on said weighing mechanism and weighed thereby, and to discontinue the drying operation after a predetermined period of time has elapsed, rotary sampling mechanism mounted for rotation adjacent said weighing mechanism and continuously sampling a flow of such material, and a chute movably mounted in position to continuously receive such material from said sampling mechanism and to discharge the same upon said sample-supporting and weighing mechanism, said chute being movable to divert such material away from said weighing mechanism when desired, a timer connected with said weighing mechanism, and automatic control means connected to said chute and said weighing mechanism and in cooperation with said timer for swinging said chute to materialdiverting position relative to said sample weighing mechanism when a sample of predetermined weight has been delivered to said sample weighing mechanism and for returning said chute into material-delivering position relative to said sample-weighing mechanism at a predetermined time thereafter.

'14. Moisture-content determining apparatus comprising, mechanism for supporting and weighing a sample of the material the moisture content of which is to be determined, sample drying mechanism mounted adjacent to said weighing mechanism and positioned to dry the sample while so supported, and connected with said 14 a, weighing mechanism to automatically commence to dry the sample when the entire sample has been deposited on said weighing mechanism and weighed thereby, and to discontinue the drying operation after a predetermined period of time has elapsed, rotary sampling mechanism mounted for rotation adjacent said Weighing mechanism and continuously sampling a fiow of such material, a chute movably mounted in position to continuously receive such material from said sampling mechanism and to discharge the same upon said sample-supporting and weighing mechanism, said chute being pivotally mounted for swinging movement about an axis transverse to its length to material-diverting position and receiving such material at a point intermediate its ends, a timer connected with said weigher mechanism, and automatic control means connected to said chute and said sampleweighing mechanism and in cooperating relation with said timer for pivoting said chute to material-diverting position relative to said sample-weighing mechanism when a sample of predetermined weight has been delivered to said sample-weighing mechanism and for returning said chute to material-delivering position relative to said sample-weighing mechanism at a predetermined time thereafter.

15. Moisture-content determining apparatus comprising a sample pan, a balance supporting said sample pan and indicating the weight of the same and its contents, drying mechanism mounted adjacent to and above said pan and directed into the interior of said pan to dry its contents, a suction conduit having a movably mounted intake terminal and having a discharge terminal, said intake terminal being movable from a non-adjacent position to a position adjacent to and above said sample pan, time regulated control mechanism connected to said conduit and related to said balance and drying mechanism to cause the intake terminal of said conduit at the end of each determination to be moved to said adjacent position relative to said sample pan, and means for inducing a negative pressure within said conduit and thereby causing the contents of said sample pan to be withdrawn therefrom and to pass through said conduit when its intake terminal is swung to such position.

16. Moisture-content determining apparatus comprising a sample pan, a balance supporting said sample pan and indicating the weight of the same and its contents, dryer mechanism mounted adjacent to and above said pan and directed into the interior of said pan to dry its contents, movably mounted suction means mounted adjacent to said pan and adjusted to be moved to a position above and in close proximity to the interior of said pan, and automatic control means related to said balance and said dryer mechanism to cause said suction means to move to such position only after the contents of said pan have been dried by said dryer mechanism and have been weighed thereafter by said balance to thereby automatically empty said pan.

l7. Moisture-content determining apparatus comprising, a sample pan, a balance supporting said sample pan and indicating the Weight of the same and its contents, drying mechanism mounted adjacent to and above said pan and directed into the interior of said pan to dry its contents, suction-actuated withdrawing mechanism movably mounted adjacent said sample pan and having an intake terminal and a discharge terminal, said intake terminal being movable from a non-adjacent position to a position adjacent to and above said sample pan, and mechanism connected to said withdrawing mechanism and with said drying mechanism and related to the latter to cause the intake terminal of said Withdrawing mechanism to be automatically moved shortly after the contents of said pan have been dried from said non-adjacent position to said adjacent position and back again, whereby the contents of the sample pan may be Withdrawn from within the confines thereof after having been dried by said drying mechanism.

18. Moisture-content determining apparatus comprising a sample pan, a balance supporting said sample pan and indicating the weight of the same and its contents, dryer mechanism mounted adjacent to and above said pan and directed into the interior of said pan to dry its contents, a conduit having an intake terminal and a discharge terminal, mounting structure movably supporting said conduit for movement of its intake terminal from a position non-adjacent to said sample pan to a position above and adjacent to said sample pan and back again, suction means connected with the discharge terminal of said conduit for inducing a negative pressure within the confines of and at the intake terminal of said conduit, mechanism connected with said conduit for moving its intake terminal from a non-adjacent position to a position above and adjacent to said sample pan and back again, and automatic control means related to said dryer mechanism and said balance to cause said conduit moving mechanism to move the intake terminal of said conduit to said adjacent position after the contents of said pan have been dried by said dryer mechanism and have been weighed thereafter by said balance to thereby automatically empty said pan.

19'. Moisture-content determining apparatus comprising a sample pan, a laterally immovable balance supporting said sample pan and indicating the weight of the same and its contents, dryer mechanism mounted adjacent to and above said pan and directed into the interior of said pan to dry the contents, a conduit having an intake terminal and a discharge terminal, mounting structure movably supporting said conduit for movement of its intake terminal from a position non-adjacent to 16 said sample pan to a position above and adjacent ,to said sample pan and back again, suction means connected with the discharge terminal of said conduit for inducing a negative pressure within the confines of and at the intake terminal of said conduit, mechanism connected with said conduit for moving its intake terminal from a non-adjacent position to a position above and adjacent to said sample pan and back again, and automatic control means constructed and arranged relative to said dryer mechanism and said balance to cause said conduit moving mechanism to move the intake terminal of said conduit to said adjacent position only after the contents of said pan have been dried by said dryer mechanism and have been Weighed thereafter by said balance to thereby automatically empty said pan and to automatically return said intake terminal of said conduit to said non-adjacent position after the contents of said pan have been Withdrawn therefrom by said conduit.

References Cited in the file of this patent UNITED STATES PATENTS Curry Dec. 24, 1912 

